The synchronizing problem is always present in all data transmission, and is solved depending on the application, demand on accuracy etc. in different ways. For example, if the Transmitter and Receiver side clocks are synchronized, possibly against a common reference, the detection of data at the Receiver side does not cause any problems of course. Synchronizing of a Receiver clock can be in a mode such that the timing information is extracted from the transmitted data signal, e.g. by time determination of its zero crossings, subsequent to which a signal corresponding to the timing information is allowed to actuate a controllable local clock signal generator. Requirements in respect to transient time and permitted error in the data transmission naturally affects the selection of the synchronizing method also.